An electrooptic assembly, such as that disclosed by Hawrylo et al. in U.S. Pat. No. 4,394,379, comprises an electrooptic device, such as a semiconductor light emitting or detecting element, mounted on a header and enclosed by a cover with a light-transmissive window mounted therein. The header generally includes a base plate having two parallel major surfaces and at least one minor surface connecting the major surfaces. The cover is typically attached to the minor surface by conventional methods such as welding or soldering. The header also includes a stud which is mounted on the first major surface of the base plate and is typically used for both heat dissipation and mounting of the electrooptic device. The electrooptic device is mounted either directly on the second major surface or on a mounting block which in turn is mounted on the second major surface.
The electrooptic device emits or detects light in a spatial distribution pattern which typically has an optical axis of symmetry representing a maximum in the intensity of the emission or the sensitivity of detection. The intensity of emission or sensitivity of detection is dependent on the angle of emergence or incidence of light on the window and thus it is desirable to have the optical axis normal to a major surface plane of the window. This is often not achieved due to variations in emission or detection characteristics of the device or mounting variations which can occur when the device is mounted on the header.